Undersea drilling templates are placed adjacent the seabed to provide a stable hole through which drillbits, drillpipes and other undersea drilling equipment are passed into holes drilled into the seabed by drilling platforms seeking oil and gas deposits. The template's main purpose is to stabilize the seabed adjacent the top of the drill hole to avoid collapsing of the wet sand adjacent the hole. The templates are generally a metal annulus having an outer diameter of about 3048 mm (12 ft) and an inner diameter of about 974 mm (38.38").
Templates are lowered to the seabed over distances ranging from 100 meters to 2500 meters by a running tool attached to the drillpipe by a box-pin thread.
When the template has been lowered to the seabed, the tension in the drillpipe is released to allow the running tool to be rotated out of engagement with the template and then pulled to the surface. A drillbit is then attached to the drillpipe and lowered to the seabed where it must be maneuvered into passing through the central hole in the template for drilling to commence.
This can be a very time-consuming process, taking from between 3 hours in shallow depths to up to 24 hours in deep depths. Further, it can be extremely difficult to maneuver the drillbit into alignment with the template hole as it must first pass through various depths of sea. Remote control submarines fitted with video cameras are often used to assist in maneuvering the drillbit into the template hole.
It is an object of the present invention to substantially overcome or at least ameliorate one or more of the prior art deficiencies.